System and method for non-contention based handover based on pre-reserved target cell uplink allocations in communication systems

Abstract

In accordance with aspects of the present invention, a method, apparatus and system for non-contention based handover based on pre-reserved target cell uplink allocations in communication systems. In one embodiment, the apparatus includes a transceiver ( 760 ) configured to communicate with a source base station and a data processor ( 750 ) coupled to the transceiver ( 760 ). The data processor ( 750 ) is configured to produce a measurement report based on a signal received from the source base station, initiate transmission of the measurement report to the source base station, process a handover command received from the source base station, and enable transmission of access bursts to a target base station in a reserved window of time on an uplink shared channel.

What is claimed is: 
     
       1. An apparatus, comprising:
 at least one data processor; and 
 at least one memory including computer program code, where the at least one memory and the computer program code are configured, with the at least one data processor, to cause the apparatus to at least: 
 communicate with a source base station; 
 produce a measurement report based at least in part on a signal received from said source base station, initiate transmission of said measurement report to said source base station; 
 process a handover command received from said source base station, said handover command comprising information about a reserved window of time; and 
 enable transmission of access bursts to a target base station in said reserved window of time on an uplink shared channel. 
 
     
     
       2. The apparatus according to  claim 1  wherein said measurement report includes a received signal amplitude and a signal transport delay. 
     
     
       3. The apparatus according to  claim 1  wherein said access bursts are at least in part based on a cell-specific radio network temporary identifier for said apparatus, an uplink power level for said transmission provided by said target base station, or a dedicated preamble employable with a random access channel procedure in a target cell. 
     
     
       4. The apparatus according to  claim 1  wherein said access bursts are transmitted in said reserved window of time with a designated starting time. 
     
     
       5. The apparatus according to  claim 1  wherein said access bursts are transmitted on said uplink shared channel until one of an acknowledgement is received from said target base station, a timeout period expires and a predetermined number of access bursts has been transmitted. 
     
     
       6. A non-transitory computer-readable medium bearing computer program code, the computer program code executed by at least one data processor to perform operations comprising:
 producing a measurement report based at least in part on a signal received from a source base station; 
 initiating transmission of said measurement report to said source base station; and 
 processing a handover command received from said source base station, said handover command comprising information about a reserved window of time; and 
 enabling transmission of access bursts to a target base station in said reserved window of time on an uplink shared channel. 
 
     
     
       7. The non-transitory computer readable medium according to  claim 6  wherein said access bursts are transmitted on said uplink shared channel until one of an acknowledgement is received from said target base station, a timeout period expires, or a predetermined number of access bursts has been transmitted. 
     
     
       8. A method, comprising:
 producing a measurement report based at least in part on a signal received from a source base station; 
 initiating transmission of said measurement report to said source base station; 
 processing a handover command received from said source base station, said handover command comprising information about a reserved window of time; and 
 enabling transmission of access bursts to a target base station in said reserved window of time on an uplink shared channel. 
 
     
     
       9. The method according to  claim 8  wherein said access bursts are at least in part based on a cell-specific radio network temporary identifier for a user equipment, an uplink power level for said transmission provided by said target base station or a dedicated preamble employable with a random access channel procedure in a target cell. 
     
     
       10. The method according to  claim 8  wherein said access bursts are transmitted in said reserved window of time with a designated starting time. 
     
     
       11. An apparatus, comprising:
 at least one data processor; and 
 at least one memory including computer program code, where the at least one memory and the computer program code are configured, with the at least one data processor, to cause the apparatus to at least: 
 determine if said apparatus has sufficient resources to accommodate user equipment and reserve a window of time on an uplink shared channel for said user equipment to transmit access bursts; and 
 transmit a message to a source base station confirming handover of said user equipment associated therewith, said message comprising information about said reserved window of time. 
 
     
     
       12. The apparatus according to  claim 11  wherein said at least one memory including computer program code is configured, with said at least one data processor, to cause the apparatus to allocate a cell-specific radio network temporary identifier, an uplink power level to be used by said user equipment, or a dedicated preamble employable with a random access channel procedure in a target cell. 
     
     
       13. The apparatus according to  claim 11  wherein said message to said source base station confirming handover of said user equipment further comprises pre-allocation uplink information for said user equipment. 
     
     
       14. The apparatus according to  claim 11  wherein said at least one memory including said computer program code is configured, with said at least one data processor, to cause the apparatus to receive said access bursts from said user equipment until one of an acknowledgement is sent to said user equipment, a timeout period expires and a predetermined number of access bursts has been transmitted. 
     
     
       15. The apparatus according to  claim 11  wherein said at least one memory including said computer program code is configured, with said at least one data processor, to cause the apparatus to reserve future uplink allocations for incoming handover of other user equipment. 
     
     
       16. A method, comprising:
 determining if a target base station has sufficient resources to accommodate user equipment; 
 reserving a window of time on an uplink shared channel for said user equipment to transmit access bursts; and 
 transmitting a message to a source base station confirming handover of said user equipment associated therewith, said message comprising information about said reserved window of time. 
 
     
     
       17. The method according to  claim 16  wherein said reserving further comprises a cell-specific radio network temporary identifier, an uplink power level to be used by said user equipment, or a dedicated preamble employable with a random access channel procedure in a target cell. 
     
     
       18. The method according to  claim 16  wherein said message to said source base station confirming handover of said user equipment further comprises pre-allocation uplink information for said user equipment. 
     
     
       19. The method according to  claim 16  further comprising reserving future uplink allocations for incoming handover of other user equipment. 
     
     
       20. A communication system, comprising:
 a source base station, including:
 a measurement report handler configured to process a measurement report from user equipment, and 
 a handover subsystem configured to select a target base station for a handover of said user equipment and to generate a handover request for said user equipment to said target base station; and 
 
 a target base station, including:
 a packet scheduler configured to determine if said target base station has sufficient resources to accommodate said user equipment and reserve a window of time on an uplink shared channel for said user equipment to transmit access bursts, and 
 a handover subsystem configured to transmit a message to said source base station confirming a handover of said user equipment, said message comprising information about said reserved window of time.